High-Starch Diet And Pancreatic Cancer

A diet high in starchy foods such as potatoes, rice and white bread may increase the risk of pancreatic cancer in women who are overweight and sedentary, according to a new study by Dana-Farber Cancer Institute, Brigham and Women’s Hospital and Harvard School of Public Health researchers.

Earlier laboratory studies have demonstrated that insulin encourages the growth of pancreatic cancer cells. Other studies have shown that people who are obese, physically inactive or have adult-onset diabetes mellitus tend to be “insulin resistant,” causing them to produce larger-than-normal amounts of insulin to compensate and putting themselves at greater risk for pancreatic cancer.

The researchers reasoned that if insulin fuels the growth of pancreatic cancer, then foods that prompt the body to produce large amounts of insulin should be associated with a greater occurrence of the disease. Knowing that the body uses insulin to burn sugar, the researchers focused on foods that raise blood levels of glucose, a sugar that is a main energy source for cells.

Data for the study came from the Nurses’ Health Study, a project at Brigham and Women’s Hospital that tracks health information on female nurses across the country. The researchers reviewed the dietary records of nearly 89,000 nurses.

The researchers found that women who were significantly overweight and physically inactive (and whose levels of glucose and insulin were therefore already above normal) were more than two-and-a-half times more likely to develop pancreatic cancer if they had a high glycemic load than if they had a low glycemic load. Interestingly, a high glycemic load did not increase pancreatic cancer risk among women who were lean and physically fit.

The researchers note that this trend had not reached the level of statistical significance due to the limited number of cancer cases in each category.

“The take-home message for women who are overweight and sedentary is that a diet high in starchy foods may increase their risk of pancreatic cancer,” says Fuchs. “Substituting less starchy vegetables such as broccoli for potatoes and rice and snacking on fruit are some simple steps that they can take to reduce this potentially serious health risk.”

Note: Nearly 30,000 men and women in the United States are diagnosed with pancreatic cancer each year, and an equal number die from it. Pancreatic cancer typically is highly aggressive and is one of the least-curable malignancies. Only four percent of the people with pancreatic cancer are alive five years after diagnosis.